title: A case of IgG lambda lymphoma occurring in a patient with previous IgG kappa lymphoma.
abstract: When a patient with non-Hodgkin's lymphoma (NHL) undergoes a relapse, immunological testing of malignant lymphocytes usually shows that the relapse cells are derived from the original tumor clone. We have observed a patient with a B cell lymphoma whose cells bore surface membrane IgG kappa at diagnosis and IgG lambda at clinical relapse 21 months later, during which time he had received multiple-drug chemotherapy. The shift from kappa to lambda light chain expression implies that the patient's apparent relapse was in fact due to the development of a second tumour. This may be another example of cytotoxic drug-induced carcinogenesis in a patient with a lymphoproliferative disorder.
mesh_terms: D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D008198:Lymph Nodes / Q000276:immunology; D008223:Lymphoma / Q000276:immunology*; D008297:Male; D011947:Receptors, Antigen, B-Cell
chemical_list: D007074:Immunoglobulin G; D007147:Immunoglobulin Light Chains; D007145:Immunoglobulin kappa-Chains; D007146:Immunoglobulin lambda-Chains; D011947:Receptors, Antigen, B-Cell